zxing/csharp/multi/ByQuadrantReader.cs
2011-10-08 10:38:07 +00:00

104 lines
3.1 KiB
C#
Executable file

/*
* Copyright 2009 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using BinaryBitmap = com.google.zxing.BinaryBitmap;
using Reader = com.google.zxing.Reader;
using ReaderException = com.google.zxing.ReaderException;
using Result = com.google.zxing.Result;
namespace com.google.zxing.multi
{
/// <summary> This class attempts to decode a barcode from an image, not by scanning the whole image,
/// but by scanning subsets of the image. This is important when there may be multiple barcodes in
/// an image, and detecting a barcode may find parts of multiple barcode and fail to decode
/// (e.g. QR Codes). Instead this scans the four quadrants of the image -- and also the center
/// 'quadrant' to cover the case where a barcode is found in the center.
///
/// </summary>
/// <seealso cref="GenericMultipleBarcodeReader">
/// </seealso>
public sealed class ByQuadrantReader : Reader
{
//UPGRADE_NOTE: Final was removed from the declaration of 'delegate '. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1003'"
private Reader delegate_Renamed;
public ByQuadrantReader(Reader delegate_Renamed)
{
this.delegate_Renamed = delegate_Renamed;
}
public Result decode(BinaryBitmap image)
{
return decode(image, null);
}
public Result decode(BinaryBitmap image, System.Collections.Hashtable hints)
{
int width = image.Width;
int height = image.Height;
int halfWidth = width / 2;
int halfHeight = height / 2;
BinaryBitmap topLeft = image.crop(0, 0, halfWidth, halfHeight);
try
{
return delegate_Renamed.decode(topLeft, hints);
}
catch (ReaderException)
{
// continue
}
BinaryBitmap topRight = image.crop(halfWidth, 0, halfWidth, halfHeight);
try
{
return delegate_Renamed.decode(topRight, hints);
}
catch (ReaderException)
{
// continue
}
BinaryBitmap bottomLeft = image.crop(0, halfHeight, halfWidth, halfHeight);
try
{
return delegate_Renamed.decode(bottomLeft, hints);
}
catch (ReaderException)
{
// continue
}
BinaryBitmap bottomRight = image.crop(halfWidth, halfHeight, halfWidth, halfHeight);
try
{
return delegate_Renamed.decode(bottomRight, hints);
}
catch (ReaderException)
{
// continue
}
int quarterWidth = halfWidth / 2;
int quarterHeight = halfHeight / 2;
BinaryBitmap center = image.crop(quarterWidth, quarterHeight, halfWidth, halfHeight);
return delegate_Renamed.decode(center, hints);
}
}
}